memcheck/tests/holey_buffer_too_small.c

#include <stdlib.h>
#include <stdio.h>

#include "../memcheck.h"

/* This test checks that VALGRIND_CHECK_MEM_IS_DEFINED correctly
   reports two errors when presented with a buffer which contains both
   undefined data and some out of range component(s), and the
   undefined data appears before the out of range components.  Should
   report 5 errors in total: the first test should report 2, the rest
   1 each. */

int main ( void )
{
   char* a;

   fprintf(stderr, "\n---- part defined, address error at end ----\n\n");
   a = malloc(8);
   a[0] = a[1] = a[2] = a[3] = a[6] = a[7] = 'x';
   VALGRIND_CHECK_MEM_IS_DEFINED(a, 9);
   free(a);

   fprintf(stderr, "\n---- part defined, address error at start ----\n\n");
   a = malloc(8);
   a[0] = a[1] = a[2] = a[3] = a[6] = a[7] = 'x';
   VALGRIND_CHECK_MEM_IS_DEFINED(a-1, 9);
   free(a);

   fprintf(stderr, "\n---- fully defined, address error at end ----\n\n");
   a = malloc(8);
   a[0] = a[1] = a[2] = a[3] = a[4] = a[5] = a[6] = a[7] = 'x';
   VALGRIND_CHECK_MEM_IS_DEFINED(a, 9);
   free(a);

   fprintf(stderr, "\n---- fully defined, address error at start ----\n\n");
   a = malloc(8);
   a[0] = a[1] = a[2] = a[3] = a[4] = a[5] = a[6] = a[7] = 'x';
   VALGRIND_CHECK_MEM_IS_DEFINED(a-1, 9);
   free(a);

   return 0;
}